Palladium-Catalyzed [4+1] Cycloaddition of 3,3-Difluoropent-4-en-2-ones with Amines: A Modular Approach to 3-Fluoropyrroles

3-Fluoropyrroles are privileged scaffolds in pharmaceutical and agrochemical applications, yet their synthesis remains challenging. Herein, we report a palladium(0)-catalyzed [4+1] cycloaddition/dehydration strategy for the efficient construction of 3-fluoropyrroles from readily available 3,3-difluoropent-4-en-2-ones and primary amines. This transformation proceeds via C-F bond activation to generate a key π-allyl-Pd(II) intermediate, followed by intramolecular addition/dehydration to furnish the heterocyclic core. The method features broad substrate compatibility, mild conditions, and scalability, enabling access to diverse 3-fluoropyrroles that are otherwise difficult to synthesize. This work provides a practical and versatile platform for the discovery of fluorinated pyrrole-based bioactive molecules.